I just want to make sure. Are you, Pool User, the same as Lisa in MO, the original poster? So are we talking about the same problem which originally sounded like a green pool, but now sounds like something appearing at the bottom of the pool. And out of all the testing I didn't see anything about Cyanuric Acid (CYA) levels which are critically important to know. If CYA is zero, then chlorine will get broken down by the sun too quickly and you'll have zero chlorine and then algae. If CYA is too high, then you need higher Free Chlorine (FC) levels to keep away algae. So it's really important to get that measured and please, please, get yourself one of the good test kits mentioned (Taylor K-2006 or tftestkits TF100), probably online since most pool stores do not carry these test kits (the Taylor K-2005 is NOT the same thing).
As for stuff on the bottom of the pool that is not algae (assuming that), it could be sand (which should feel gritty) or pollen (though normally floats on the surface first). If it's pollen, you can use a skimmer sock which usually helps catch it. If you can get a sample of it, then if it's really gritty and hard, it's sand. If it's slimy, it's probably algae (pollen is more grimy or even a little gritty than slimy), but looking under a (cheap) microscope is definitive since pollen is round balls, sometimes with spikes, while algae is semi-transparent, usually more rectangular and sometimes in filaments with multiple cells.
As for "Drop It", that sounds like a flocculant so if that is clearing up the pool it is consolidating whatever particles that were there, which could be almost anything -- including metals since copper carbonate will fall out with flocculant just as algae or pollen would. The problem is that until you know what your FULL pool water chemistry measurements are, you can't know how to prevent the problem from reoccurring. With the test kits I mentioned you can accurately measure Free Chlorine (FC), Combined Chlorine (CC), pH, Total Alkalinity (TA), Cyanuric Acid (CYA) and Calcium Hardness (CH).
By the way, what kind of shock do you already have? Look on the bottle and see if it says Cal-Hypo or if it says Dichlor (or something like Sodium Dichloro-s-Triazine-Trione Dihydrate). If the latter, then that is USELESS as it not only adds chlorine, but increases CYA as well so if your CYA is high then that just makes the problem worse. Even with Cal-Hypo you need to be careful that your CH doesn't get too high as this will cause cloudiness (and scaling, if really high, along with high pH).
Finally, as for lowering TA, the pool store is wrong. You CAN lower the TA, but it requires a combination of low pH and lots of aeration, with adding acid to keep the pH low (since aeration will make the pH rise). The procedure is described in
this post. But first, get a good test kit and post a full set of numbers so we can help get rid of the green and/or stuff on the bottom problem. The TA can be dealt with later.
Richard
but we are not going to fight with it too much more its swimable just cloudy... and its almost time to cover it up for the season usualy do so after labor day